hot "straight" guy

ok so i am a very bi-curious guy and i have a good friend who says hes straight. we are both 18 our families like to travel together. there are a couple other younger guys in the group and we all usually share a room when we go places. he has a very nice body and walks around in his tight underwear a lot which i love. there are signs i think hes gay-he popped a boner after seeing guys in speedos (could have been something else)-he hasnt had a girlfriend but is talking to some girl now (it could be a show)-i think he flirts-he lets me grab stuff thats on his lap and i try to keep my hand there to see his reaction (nothing)i have had fantasies about him and he doesnt know im curious and i dont know if he is. i wanna make a move and see what happens but no one knows i like men. should i try to get him to make it? which one and how? please help

i need to make a subtle move to see his reaction. it needs to be big enough for him to notice but small enough so he doesnt no i am gay till i know he is too. as much as i want to fuck him so bad i need to wait thanks though